Expedition Four
Commander Yury Onufrienko and Astronaut Dan Bursch completed a five-hour,
59-minute spacewalk outside the International Space Station today, installing
six thruster deflectors at the rear of the Zvezda Service Module, retrieving
and replacing a device to measure material from the thrusters and installing
a ham radio antenna and its cabling. They also installed three materials
experiments on Zvezda’s exterior and a physics experiment.

With Onufrienko
and Bursch working outside, Astronaut Carl Walz served as intravehicular
crewmember, helping to coordinate the spacewalk and maneuvering the
station’s robotic arm, Canadarm2, to allow its television cameras
to view the spacewalk. This was the 33rd spacewalk for station assembly
and outfitting and the eighth conducted from the station itself. Onufrienko
and Bursch, wearing Russian Orlan spacesuits, installed six plume deflectors
around attitude control thrusters at the rear of the Zvezda module.
The deflectors are designed to limit deposits on the outside of the
station that result from the firing of those thrusters.

The spacewalkers
also removed an experiment called Kromka situated near one of the thruster
groups. The experiment captured material that results from thruster
firings. It will be returned to Earth in early May aboard a Soyuz spacecraft.
By studying the captured materials, engineers will gain a better understanding
of the nature of the deposits. Onufrienko and Bursch installed a virtually
identical new Kromka experiment in the same place. Future analysis of
the materials it captures will provide information on the effect of
the plume deflectors. They also installed a ham radio antenna and associated
cabling at the rear of Zvezda. The antenna is the second of four that
eventually will be situated around the back of the module. Onufrienko
and Walz had installed the first antenna during a Jan. 14 spacewalk.

Onufrienko and
Bursch also attached a physics experiment called Platan to Zvezda. Platan
is designed to capture low-energy heavy nuclei from the sun and from
outside the solar system. In addition, they installed three materials
experiments, called SKK for their Russian acronym, on Zvezda. The experiments
examine effects of the harsh environment of space on a wide range of
materials. The spacewalkers also installed fairleads on Zvezda handrails.
The fairleads, called pigtails, keep spacewalkers’ tethers from
fouling equipment or experiments on the module’s exterior. Throughout
the spacewalk, they took photos to document their work.

Information on
the crew's activities aboard the space station, future launch dates
and times, as well as station sighting opportunities from anywhere on
the Earth, is available on the internet at: http://spaceflight.nasa.gov.
Details on station science operations can be found on an internet site
administered by the Payload Operations Center at NASA's Marshall Space
Flight Center in Huntsville, Ala., at: http://www.scipoc.msfc.nasa.gov.
The next ISS status report will be issued Feb. 1.

-END-

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